Field of the Inventions
The present inventions relate to a power transmitting apparatuses for arbitrarily transmitting or cutting-off the rotational driving power of an input member to or from an output member.
Description of the Related Art
In general, the power transmission apparatus for a motorcycle is intended to arbitrarily perform transmission of or cutting-off of the driving power of an engine to or from a transmission and a driving wheel and comprises an input member connected to an engine-side, an output member connected to a transmission and a driving wheel-side, a clutch member connected to the output member, and a pressure member able to approach or separate from the clutch member. The driving power can be transmitted by approaching and press-contacting a plurality of driving-side clutch discs and driven-side clutch discs to each other or cut off by separating them from each other and releasing the press-contacting force acting on them.
As disclosed in JP 2010-60106 A, a power transmitting apparatus of the prior art has been proposed which comprises weight members arranged in radially extending grooves formed on a clutch housing. The power transmitting apparatus press-contacts driving-side clutch discs and driven-side clutch discs due to movement of the weight members from their radially inward positions to radially outward positions caused by a centrifugal force due to rotation of the clutch housing. The power transmitting apparatus includes an actuating member operated by a manually operating means for releasing the press-contacting force between the driving-side clutch discs and the driven-side clutch discs.
More particularly, the power transmitting apparatus of the prior art comprises a first pressure plate actuated by the actuating member and a second pressure plate actuated by movement of the weight members, and the driving-side clutch discs and the driven-side clutch discs are arranged between the first and second pressure plates. In addition, the cutting-off of power transmission due to manual operation of the actuating member is performed by releasing the press-contacting force between the driving-side clutch discs and driven-side clutch discs by moving the first and second pressure plates, and the power due to movement of the weight members is performed by press-contacting the driving-side clutch discs and the driven-side clutch discs by moving the second pressure plate.
According to the power transmitting apparatus of the prior art, it is possible to apply the centrifugal force to the weight members due to rotation of the clutch housing caused by engine rotation, to press-contact the driving-side clutch discs and the driven-side clutch discs by actuating the first pressure plate, and to release the press-contacting force between the driving-side clutch discs and the driven-side clutch discs by actuating the second pressure plate while keeping position of the weight members (radially outward position) during cutting-off of the power transmission by operating the actuating member by manual operation. Accordingly it is possible to improve the operability of the power transmitting apparatus during cutting-off operation of the power transmission.